黄河口凹陷莱北斜坡带玄武岩发育区砂岩成岩特征、孔隙流体及储层控制因素

为探究黄河口凹陷研究区玄武岩喷发对相关砂岩储层成岩作用的影响，从粘土矿物、沸石及微量元素分析入手，明确莱北斜坡带古近系不同层位孔隙流体性质变化，建立火成岩发育区砂岩储层的成岩-孔隙演化模式：沙一段和沙二段沉积时期，受小规模玄武岩喷发与干旱-半干旱气候条件下碱性水介质影响，砂岩中钠长石化和碳酸盐岩胶结普遍，碎屑颗粒表面发育白云石膜，见石英溶蚀现象；东三段三角洲砂岩储层受沙一段暗色泥岩中析出的卤水及陆源淡水输入影响，叠加后期富铁镁质孔隙水混合影响，成岩作用以弱碱性水介质条件下沸石溶解、粘土矿物转化与钠长石化为主；东一段和东二段沉积时期玄武岩广泛发育，不稳定富铁镁矿物的强烈水解，导致孔隙流体富含铁镁质，以低硅沸石的沉淀与溶蚀为特色。与玄武岩喷发相关的局部沸石沉淀与溶解以及玄武岩喷发形成的“工字型”构架对东营组砂岩孔隙的保存有利；而沙一段和沙二段沉积时期碱性水介质下形成的栉壳状白云石抑制了石英的次生加大，碱性水介质下的石英溶蚀现象普遍，有利于其砂岩孔隙的保存。

Diagenesis,Pore Fluid and Controlling Factors of Reservoir Quality in the Basalt Area of Laibei Slope Zone,Huanghekou Sag

In order to explore the influence of basalt eruption on reservoir diagenesis in Huanghekou sag, clay mineral, zeolite and trace elements in the Laibei slope zone were studied to make it clear that the pore fluid changes in different formation of Paleogene and then to establish the reservoir diagenesis and pore evolution model in igneous rocks area. In the period of the first and second members of the Shahejie Formation, under the influence of alkaline water medium formed in the small-scale basalt eruption environment and arid-semiarid climate, albitization and carbonate cementation developed universally and dolomite coat grew on grain surface, also we can see the phenomena of quartz dissolution. In the third member of the Dongying Formation, the delta reservoir was influenced by the brine precipitation in dark mudstones of the first member of Shahejie Formation and terrestrial freshwater input, also late rich mafic pore water mixing effect, so the main diagenesis are zeolite dissolution, clay mineral transformation and albitization in alkalescence water medium conditions. In the period of the first and second members of the Dongying Formation, it is characterized by extensive eruption basalt, strong hydrolysis of minerals rich in iron and magnesium element which led to the pore fluid rich in mafic, and the precipitation and dissolution of low silica zeolite. The local precipitate and dissolution of zeolite and “I-shaped” framework associated with basalt eruption is in favour of sandstone pore preservation of Dongying Formation. During the deposition of the first and second members of Shahejie Formation, pectinate dolomite coat which inhibited the quartz overgrowth under the alkaline water medium and the phenomena of quartz dissolution is beneficial to the preservation of the sandstone pore.